Superstorm93 Posted January 21, 2017 Share Posted January 21, 2017 Mid-upper disturbance is really ejecting now. Best dynamics and wind profiles will not be far behind Link to comment Share on other sites More sharing options...
Superstorm93 Posted January 21, 2017 Share Posted January 21, 2017 Two areas of rotation on one cell Link to comment Share on other sites More sharing options...
Indystorm Posted January 21, 2017 Share Posted January 21, 2017 Warm fronts at night can be very active. Along with night time tors in winter in the South. Link to comment Share on other sites More sharing options...
janetjanet998 Posted January 21, 2017 Share Posted January 21, 2017 MESOSCALE DISCUSSION 0096 NWS STORM PREDICTION CENTER NORMAN OK 0532 PM CST SAT JAN 21 2017 AREAS AFFECTED...PORTIONS OF FAR NORTHEAST TEXAS...NORTHERN LOUISIANA...SOUTHERN/CENTRAL ARKANSAS...AND WESTERN MISSISSIPPI CONCERNING...TORNADO WATCH 16... VALID 212332Z - 220130Z THE SEVERE WEATHER THREAT FOR TORNADO WATCH 16 CONTINUES. SUMMARY...THE THREAT FOR TORNADOES, VERY LARGE HAIL, AND DAMAGING WIND GUSTS CONTINUES ACROSS MUCH OF WATCH 16. ADDITIONALLY, DOWNSTREAM WATCH ISSUANCE WILL LIKELY BE NEEDED ACROSS NORTHEASTERN LA, SOUTHEASTERN AR, AND WESTERN MS WITHIN 2-3 HOURS. DISCUSSION...MULTIPLE SUPERCELLS HAVE FORMED LATE THIS AFTERNOON ACROSS WEST-CENTRAL PORTIONS OF WATCH 16, IN RESPONSE TO LOW-LEVEL CONFLUENCE NEAR A SURFACE TROUGH/WARM FRONT AND MID/UPPER-LEVEL ASCENT ON THE NOSE OF AN IMPULSE OVER EASTERN TX. A SURFACE LOW WAS ANALYZED NEAR THE TX/LA BORDER AT 23Z, WITH A WARM FRONT EXTENDING TO ITS SOUTHEAST TOWARDS NEW ORLEANS. NEAR THIS BOUNDARY, BACKED SURFACE WINDS ARE ENHANCING STORM-RELATIVE HELICITY SUFFICIENTLY FOR LOW-LEVEL MESOCYCLOGENESIS. INDEED, A FAIRLY PROMINENT TORNADIC DEBRIS SIGNATURE WAS NOTED ACROSS FAR NORTHEAST MARION COUNTY / FAR SOUTHEAST CASS COUNTY IN TX OVER THE LAST 20-30 MINUTES AND ANOTHER RECENTLY OBSERVED OVER NORTHEAST BOSSIER PARISH. MORE SUPERCELLS ARE LIKELY TO FORM FARTHER SOUTH, WITH THE POTENTIAL FOR TORNADOES CONTINUING AS THEY PROGRESS NORTHEAST, ESPECIALLY WHEN THESE CELLS APPROACH THE AFOREMENTIONED SURFACE FRONT. MOREOVER, STEEP MID-LEVEL LAPSE RATES NOTED IN 18/20Z REGIONAL SOUNDINGS AND AMPLE EFFECTIVE SHEAR WILL MAINTAIN THE POTENTIAL FOR ROBUST ORGANIZED UPDRAFTS CAPABLE OF VERY LARGE HAIL. INDEED, RECENT KSHV DATA HAVE DEPICTED SEVERAL BROAD/DEEP ZDR COLUMN AND RING STRUCTURES ALOFT, SUGGESTING HAILSTONE GROWTH SHOULD BE QUITE EFFICIENT. ..PICCA.. 01/21/2017 Link to comment Share on other sites More sharing options...
Amped Posted January 21, 2017 Share Posted January 21, 2017 1 minute ago, Indystorm said: Warm fronts at night can be very active. Along with night time tors in winter in the South. Don't forget about tomorrow. Link to comment Share on other sites More sharing options...
SmokeEater Posted January 21, 2017 Share Posted January 21, 2017 Structural damage in and around Plain Dealing, LA per Sheriff, home severely damaged in Scottsdale, TX. Link to comment Share on other sites More sharing options...
monsoonman1 Posted January 21, 2017 Share Posted January 21, 2017 Natchez, LA might be getting hit right now. Could be debris sig, hard to tell. Link to comment Share on other sites More sharing options...
SluggerWx Posted January 22, 2017 Share Posted January 22, 2017 Discrete cells all over LA, Western MS is going to be a seriously dangerous place this evening. Link to comment Share on other sites More sharing options...
Indystorm Posted January 22, 2017 Share Posted January 22, 2017 7 minutes ago, monsoonman1 said: Natchez, LA might be getting hit right now. Could be debris sig, hard to tell. I think you mean Natchitoches. Link to comment Share on other sites More sharing options...
monsoonman1 Posted January 22, 2017 Share Posted January 22, 2017 2 minutes ago, Indystorm said: I think you mean Natchitoches. There's a small community southeast of Natchitoches called Natchez. Link to comment Share on other sites More sharing options...
Chinook Posted January 22, 2017 Share Posted January 22, 2017 No, the hook echo was directly over Natchez, or perhaps 1 mile from downtown. The heavy rain/hail was near Natchitoches. I agree there's a reasonable chance that produced a tornado in Natchez. Link to comment Share on other sites More sharing options...
Jim Martin Posted January 22, 2017 Author Share Posted January 22, 2017 2 minutes ago, Indystorm said: I think you mean Natchitoches. It is Natchez. Link to comment Share on other sites More sharing options...
MattPetrulli Posted January 22, 2017 Share Posted January 22, 2017 Southern storm Link to comment Share on other sites More sharing options...
SmokeEater Posted January 22, 2017 Share Posted January 22, 2017 New TW heading for Plain Dealing where there's already tornado damage. Link to comment Share on other sites More sharing options...
SluggerWx Posted January 22, 2017 Share Posted January 22, 2017 Classic structure on this cell with potential debris signature near Natchez, LA. Link to comment Share on other sites More sharing options...
Indystorm Posted January 22, 2017 Share Posted January 22, 2017 I stand corrected on the small town of Natchez LA. Thanks. Link to comment Share on other sites More sharing options...
Indystorm Posted January 22, 2017 Share Posted January 22, 2017 Strong, long lived tornadoes now being mentioned in new SPC meso for se LA and southern MS. Link to comment Share on other sites More sharing options...
janetjanet998 Posted January 22, 2017 Share Posted January 22, 2017 not to beat a dead horse but despite debris up 8-10k feet, a mention of debris by SPC, and pictures of several large tornadoes, the "strongest" warning or statement out of SHV was a funnel cloud was reported.....and the rest radar indicated... no mentions of radar confirmed or spotter confirmed.... if you just read the warnings/statements like most of the public does there are no tornado touchdowns and one funnel cloud did I miss something Link to comment Share on other sites More sharing options...
SmokeEater Posted January 22, 2017 Share Posted January 22, 2017 4 minutes ago, janetjanet998 said: not to beat a dead horse but despite debris up 8-10k feet, a mention of debris by SPC, and pictures of several large tornadoes, the "strongest" warning or statement out of SHV was a funnel cloud was reported.....and the rest radar indicated... no mentions of radar confirmed or spotter confirmed.... if you just read the warnings/statements like most of the public does there are no tornado touchdowns and one funnel cloud did I miss something Those photos were sent to them almost real time in NWS Chat too, they really haven't been saying much other then they're watching certain cells. Link to comment Share on other sites More sharing options...
Indystorm Posted January 22, 2017 Share Posted January 22, 2017 Low and mid level helicity slowly increasing in central and se LA. Dews in upper 60's. Link to comment Share on other sites More sharing options...
janetjanet998 Posted January 22, 2017 Share Posted January 22, 2017 TOR warning for Mobile AL Link to comment Share on other sites More sharing options...
Indystorm Posted January 22, 2017 Share Posted January 22, 2017 To be honest I think even SPC must be a bit surprised at the level of tor warnings around SHV. Earlier discussion focused on hail and tors were not initially expected till later in the evening. Link to comment Share on other sites More sharing options...
MattPetrulli Posted January 22, 2017 Share Posted January 22, 2017 PDS watch. Link to comment Share on other sites More sharing options...
monsoonman1 Posted January 22, 2017 Share Posted January 22, 2017 90/80 probabilities for South AL PDS watch Link to comment Share on other sites More sharing options...
MattPetrulli Posted January 22, 2017 Share Posted January 22, 2017 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Central and southern Alabama Western and central Florida Panhandle Small part of southeastern Mississippi Coastal Waters * Effective this Saturday night and Sunday morning from 650 PM until 300 AM CST. ...THIS IS A PARTICULARLY DANGEROUS SITUATION... * Primary threats include... Several tornadoes and a few intense tornadoes likely Scattered damaging winds and isolated significant gusts to 75 mph possible Isolated very large hail events to 2.5 inches in diameter possible SUMMARY...A cluster of storms now moving into extreme southwestern Alabama is the first of what likely will be several areas of severe weather moving across this watch overnight. As a warm front moves northward across the region, conditions will moisten and destabilize considerably amidst strong vertical shear. The resulting parameter space is one often associated with long-lasting, intense tornadoes rated EF2 or greater. The tornado watch area is approximately along and 100 statute miles north and south of a line from 80 miles north of Mobile AL to 50 miles south of Columbus GA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Link to comment Share on other sites More sharing options...
jrips27 Posted January 22, 2017 Share Posted January 22, 2017 2 minutes ago, monsoonman1 said: 90/80 probabilities for South AL PDS watch My goodness. That sounds almost high risk level. Curious to see the next SPC update. Link to comment Share on other sites More sharing options...
janetjanet998 Posted January 22, 2017 Share Posted January 22, 2017 AY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0655 PM CST SAT JAN 21 2017 VALID 220100Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN ARKANSAS TO NORTHERN LOUISIANA INTO WESTERN MISSISSIPPI... ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST MISSISSIPPI INTO SOUTHERN AND SOUTH CENTRAL ALABAMA AND SOUTHWEST GEORGIA... ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE LOWER MISSISSIPPI VALLEY INTO MUCH OF THE GULF COASTAL STATES... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE LOWER MISSISSIPPI VALLEY INTO MUCH OF THE SOUTHEAST STATES... ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE LOWER AND MIDDLE MISSISSIPPI VALLEY INTO MOST OF THE SOUTHEAST STATES... ..SUMMARY SEVERE STORMS ARE WILL PERSIST THIS EVENING AND INTO THE OVERNIGHT FROM PARTS OF THE LOWER MISSISSIPPI VALLEY INTO THE GULF COAST STATES. SOME OF THE STORMS WILL BE CAPABLE OF PRODUCING SIGNIFICANT SEVERE WEATHER INCLUDING A STRONG TORNADOES AND VERY LARGE HAIL. ..LOWER MISSISSIPPI VALLEY THROUGH THE GULF COAST STATES EARLY THIS EVENING A WARM FRONT EXTENDS FROM THE GULF COAST THROUGH LA, SOUTHWEST AR AND OK. THIS BOUNDARY WILL CONTINUE TO ADVANCE NORTH INTO THE GULF COAST STATES AND SERVE AS A FOCUS FOR SEVERE STORMS TONIGHT. SEVERE THUNDERSTORMS INCLUDING A FEW SUPERCELLS ARE UNDERWAY FROM NORTHERN LA INTO SOUTHERN AR AND ARE DEVELOPING IN ASSOCIATION WITH ASCENT ATTENDING A PROGRESSIVE VORTICITY MAXIMUM LOCATED IN THE EXIT REGION OF A STRONG UPPER JET. THESE STORMS ARE EMBEDDED WITHIN 45-50 KT EFFECTIVE BULK SHEAR, AND 0-1 KM HODOGRAPHS ARE SUFFICIENT FOR LOW-LEVEL MESOCYCLONES. THE CAPE/SHEAR PARAMETER SPACE WILL CONTINUE TO SUPPORT THE RISK FOR VERY LARGE HAIL AND TORNADOES THIS EVENING. THE ATMOSPHERE HAS DESTABILIZED IN VICINITY OF THE WARM FRONT WITH STEEP LAPSE RATES AND A CORRIDOR OF MLCAPE FROM 1000-1500 J/KG FROM THE LOWER MS VALLEY INTO THE GULF COASTAL AREA. ADDITIONAL STORMS ARE DEVELOPING ALONG AND JUST NORTH OF THE WARM FRONT FROM THE CENTRAL GULF COAST INTO SOUTHERN LA. THE LOW-LEVEL JET SHOULD UNDERGO A SIGNIFICANT INCREASE OVER THE GULF COAST STATES TONIGHT IN RESPONSE TO MASS ADJUSTMENTS WITHIN EXIT REGION OF APPROACHING UPPER JET. THIS PROCESS WILL PROMOTE ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG AND JUST NORTH OF THE WARM FRONT WITH THETA-E ADVECTION BENEATH STEEP MID-LEVEL LAPSE RATE PLUME CONTRIBUTING TO MODERATE INSTABILITY. THE COUPLED JET STRUCTURE WILL RESULT IN VERY FAVORABLE VERTICAL WIND PROFILES FOR SUPERCELLS WITH LOW-LEVEL MESOCYCLONES. MIXED MODES WITH BOTH DISCRETE CELLS AND CLUSTERS ARE LIKELY. GIVEN THE SHEAR/INSTABILITY PARAMETER SPACE, SOME SUPERCELLS WILL BECOME CAPABLE OF PRODUCING STRONG TORNADOES IN ADDITION TO LARGE HAIL AND DAMAGING WIND. Link to comment Share on other sites More sharing options...
OhioWX Posted January 22, 2017 Share Posted January 22, 2017 Damaging tornado north of Colfax, LA. Link to comment Share on other sites More sharing options...
Chinook Posted January 22, 2017 Share Posted January 22, 2017 There's a fairly distinguishable hook echo with a velocity couplet, tornado warned storm, Aloha, LA Link to comment Share on other sites More sharing options...
monsoonman1 Posted January 22, 2017 Share Posted January 22, 2017 Likely a strong/violent tornado east of Aloha, LA. Debris lofted at least 10000 feet Link to comment Share on other sites More sharing options...
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